Centrifugal bowl with conical disks having distributing holes



Jan. 12, 1954 ITI-I CONICAL DISKS HAVING DISTRIBUTING HOLES Filed June2O 1951 P. H. s'rAAFF 2,665,843 CENTRIFUGAL BOWL W INVENTOR. berWz'ldz'ng Szocf f XBYM, Y i??? Patented Jan. l2, 1954 UNiTeo sTATesp NTorric CENTRIFUGAL BOWL WITH CONICAL DISKS HAVING DISTRBUTING HOLES PerHilding Staa, Bromma, Sweden, assignor to Aktiebolaget Separato 4:Claims.

This invention relates to an improvement in centrifugal bowls designedfor the separation of sludge-containing liquids between conical discs inthe bowl chamber, the discs having distributing holes for the liquid.

In the centrifugal separation of liquids containing a particularlysticky sludge, it has been found that sludge deposits are formed on theedges of the distributing holes of the discs at the side of the holeswhere the sludge passes through them, that is, usually the side which isclosest to the periphery of the centrifugal bowl. When separatingneutralized sour cream, for example, sludge is deposited on the outeredges of the distributing holes in the discs. These deposits may growuntil they extend around the hole and may even finally clog it, but theymay also cause a clogging of the inter-disc space closest to the holes.In this way, an unbroken sludge string may nally be formed, extendingthrough all the superimposed distributing holes. As the number of holesin each disc is generally three to six, equidistantly spaced, they maybecome clogged to such an extent that the separating effect of themachine is reduced considerably. When separating sour cream, theseparating effect may drop quite rapidly to nil.

According to the invention, this problem is solved by making the edgesor rims of at least some of the distributing holes chamfered on thatside where the sludge discharges through the holes. I have found that inthis way even a very sticky sludge will pass through the distributingholes in the discs without the tendency to clog them. By reason of thesecharnfered edges of the disc holes, the sludge passing through the holeswill have no holding points on which a core of deposition may be formedand grow, but the sludge will slide off or be cut off the edges, underthe action of the centrifugal force in the bowl, and proceed between thediscs.

The clogging of the holes in conventional discs of centrifugalseparators usually starts between the lower discs. Depending upon theliquid to be separated, it may therefore be sufficient to chamfer theedges of only the first discs, reckoned in the direction in which theliquid passes through the holes.

The invention will now be described in more detail with reference to theaccompanying drawing, in which:

Fig. 1 is a vertical sectional View of part of a centrifugal bowl,showing the outer part of a number of discs made according to theinvention;

and

r, Stockholm, Sweden, a

Fig. 2 is a face view of a portion of one of the discs shown in Fig. 1.

In the drawing, the conical discs l are provided with distributing holes2 through which the liquid to be separated ows in the directionindicated by the arrow. The sludge, being of greater specific gravitythan the liquid, tends to move radially outward toward the peripheralwall d of the centrifugal bowl and therefore passes through thedistributing holes 2 along the edges thereof nearest the wall li, thatis, along the outer edges of the holes. These outer edges of thedistributing holes are charnfered, as shown at 3. Thus, the holespresent sharp outer edges 3 pointing generally radially inward towardthe rotation axis of the bowl and away from the adjacent peripheral walli of the bowl and the peripheral anges 5 of the discs. As a result, thesludge is prevented from depositing on these edges, due

to their radial-like disposition and their cutting action on the sludgeunder the centrifugal force in the bowl.

I claim: 1. In a centrifugal separator bowl containing conical discsprovided with distributing holes, for

the separation of liquids containing sludge tending to clog the discs,the improvement which resides in at least some of the distributingholes, at the margins thereof where the sludge passes through the holes,being formed by chainfered edges of the discs, said chamfered edgesforming sharp margins of the holes pointing generally radially of therotation axis of the bowl and toward the opposite margins of therespective holes.

2. In a centrifugal separator bowl containing conical discs providedwith distributing holes, for the separation of liquids containing sludgetending to clog the discs, the improvement which resides in at leastsome of the distributing holes being formed by chamfered edges of thediscs at the outer margins of the holes nearest the adjacent peripheralwall of the bowl, whereby the holes present sharp outer edges pointingaway from said adjacent wall.

3. In a centrifugal separator bowl containing conical discs providedwith distributing holes, for the separation of liquids containing sludgetending to clog the discs, the improvement which resides in at leastsome of the distributing holes being formed by chamfered edges of thediscs at the outer margins of the holes nearest the adjacent peripheralwall of the bowl, whereby the holes present sharp outer edges pointingaway from said adjacent wall, said chamfered edges bef' ing provided ononly the first few of said discs,

reckoned in the direction in which the liquid passes through the holes.

4. A centrifugal separator disc which comprises a conical disc bodyhaving distributing holes, the disc body also having chamfered edgesforming the margins of said holes nearest the adjacent outer peripheryof the disc, whereby the holes present sharp outer edges pointing awayfrom said periphery.

PER HILDING STAAFF.

References Cited in the ille of this patent UNITED STATES PATENTS Number5 802,150 1,731,999 1,870,608

